The bank made the liquidity injection after allowing a credit crunch to happen in late June as a warning against risky lending practices.

It set the reverse rate to be paid at 4.4%, much higher than the last official guidance of 3.35%.

"The [high rate] could ... serve as a signal that the era of ultra loose money and easy money is over and liquidity has to be appropriately priced," said Wee-Khoon Chong, an economist at Société Générale in Hong Kong.